Abstract

Objective: Bromodomain-containing protein 4 (BRD4) is integral to the regulation of cell growth and differentiation. Inhibition of BRD4 can impede the expression of its associated genes, thereby suppressing cancer cell growth. This study investigates the potential anti-cancer properties of OPT-0139, a novel inhibitor targeting BRD4. Method: Human hepatic carcinoma cell lines (SK-Hep1 and Huh-7) were employed to explore the impact of OPT-0139 treatment, both singly and in combination with Sorafenib. Cell viability, proliferation, cell cycle arrest, and apoptotic cell death were assessed using MTT and ATP assays, flow cytometry, Annexin V assay, and caspase-3 activity assay. The expression of BRD4 and apoptosis-related molecules was evaluated via RT-PCR and Western blot. An in vivo experiment utilizing a mouse xenograft model analyzed tumor growth, weight, and mRNA levels. Results: OPT-0139 significantly reduces cell viability and proliferation, inducing cell cycle arrest and apoptotic cell death. The mouse xenograft model demonstrates significant alterations in tumor growth and the expression of BRD4 and apoptosis-related proteins. Combined treatment with Sorafenib synergistically enhances apoptotic cell death and suppresses tumor growth, both in vitro and in vivo. Conclusion: This investigation validates OPT-0139's efficacy and mechanism in human hepatic carcinoma cell lines. The study underscores OPT-0139's potential as a promising therapeutic agent for human hepatocellular carcinoma.